Process and apparatus for producing finely divided lead and lead compounds



` .P. KEMP EI'AL v.. u N I FS uw NU I0 WP M10 w03 R09 1 PD A 1 REO O FLS. .D S .t www. ADS RA AEd PLS P 1 Anni. 4 EF DD NI AV I s SD `.E C O R P Nov. 5, 1935.

PAUL-KEMP' Patented Nov. 5, 1935 PROCESS AND APPARATUS FOR. PRODUCING FINELY DIVIDED LEAD AND LEAD COM- POUNDS Paul Kemp, Perchtoldsdorf, and Emanuel Feuer, Liesing, Austria Application September 30, 1933, Serial No. 691,680 In Austria September 7, 1932 3 claims. (c1. 23-146) Our invention relates to an improved method for the prod uctlon of iinely divided lead and lead compounds.

In the production of lead oxide, it is old in the art to atomize lead in externally heated boilers or rotating tubes, provided with suitable centrifugal devices, and to pass gas or vapors which oxidize the lead through such boilers or tubes.

We have succeeded in providing a method for the production of iinely divided lead and lead compounds, particularly oxide of lead, which presents a number of substantial advantages over existing methods.

In the first place, by our method we completely obvlate all external heating and the heat which is necessary to maintain lead atomization in a revolving tube is provided exclusively by heating gases acting directly on the lead. This feature not only greatly simpliiles and reduces the cost of the apparatus but also effects a great economy in fuel as compared with prior art methods.

A further vadvantage of our method is attained by using heating gases which neither react with nor oxidize the lead in the atomizing chamber. By using such non-reacting and non-oxidizing gases, the heat of reaction of the burning lead may be used, for example, to heat a container for lead which is to be added to the melt, this container being arranged in the chamber in which 0 the atomized lead is burnt and such additional lead may flow directly to the atomizing chamber.

By operating as above, where the atomization and oxidation of the lead are effected in separate chambers, uninterrupted and unimpeded production of lead oxide is possible while in prior art methods, in which oxidation occurs in the atomizing chamber itself, ordinarily periodical interruption of operation is necessary because incrustation of oxide of lead, which impedes further atomization, forms on the walls of the apparatus on the lead bath itself`and on the mechanism such as agitators, ribs, etc. which serve for atomizing purposes.

The atomization of the lead may beV effected in any suitable manner, for example by providing on the inner wall of the rotating tube devices which elevate and drop the iiuid lead during rotation. Acceleration of atomization may be achieved by permitting thel descending lead to impact on conical or otherwise suitably formed ribbed surfaces secured to a rapidly rotating shaft within the drum. By proper angular co- Il hurled against the outlet end of the Finely divided lead compounds have heretofore been produced by converting the fluid lead into the vapor stage and then condensing it. 'I'he present method differs from this type of operation primarily in the fact that in our invention the 5 ne division of the lead is eilected without converting it into the vapor stage and the directly acting heating gases perform only the function of maintaining the lead at that temperature which is necessary for atomizing the uid lead. It is obvious that in view of the great difference be'- tween the melting and vaporizing temperatures of the lead, the caloric expenditure in our method is only a fraction of that necessary in the vaporizing method.

The accompanying drawing is a vertical crosssection of an apparatus suitable for the practiceof our method. I denotes a coke burning furnace provided with a grate 2 supporting a charge of coke.3. The heating gases from the furnace I pass into the atomizing chamber 4, which is constructed as a rotating tube, and these gases maintain the temperature in the chamber 4 at the value necessary for atomization. The lead which is raised during rotation by suitable means (not shown) drops onto a plurality of conical surfaces 5 which are secured to a rapidly rotating shaft (not shown) thus atomizing the lead. The atomized lead together with the outiiowing gases and with the air which flows in through the adjustable opening 6, ows in the direction of the arrows into the rotatably arranged furnace chamber 1 in which the combustion of the lead takes place. The dimensions of the oxidizing chamber are preferably such that the speed of the stream of gas issuing out of the atomizing chamber is reduced to such an extent that the lead dust precipitates in the oxidizing chamber. Arranged in the oxidizing chamber 'I is a container 8, for example of cast iron, wherein the lead which is introduced through the openings I0 and II is melted by the heat present in the combustion chamber, whereupon the iiuid lead passes through the overflow tube 9 into-the atomizing chamber. The gases are drawn by a suction device (not shown) through the conduit I2 into a purifying installation. I n the base of the combustion chamber 'I we may provide steel balls or the like for the purpose of so comminuting any lumps of oxide of lead which may form in the course of oxidizing the lead, that the balls, acting somewhat like a ball mill, make further grinding superuous. The resulting oxide of lead is discharged through closable openings I3.

What we claim as new and desire to secure by Letters Patent oi the United States isz- .1. In a method of producing ilnely divided lead oxide which comprises melting lead and atomizing the molten lead in a rotary furnace, the steps which consist in maintaining the temperature of the molten lead ready for atomization solely by means of the heat of heating gases acting directly on the lead, atomizing the molten lead in one chamber and thereafter passing over to another chamber, thel oxidation of the atomized lead being carried out in said other chamber by means of an oxidizing gas introduced into the same.

2. In a method oi' producing nely divided lead oxide, which comprises melting lead and atomizing the molten lead in a rotary furnace, the steps which consist in maintaining the temperature of the molten lead ready for atomization solely by means of heat of heating gases acting directly on the lead, atomizing the molten lead in one chamber and thereafter passing over to another chamber, the oxidation of the atomized lead being carried out in said other chamber by means of an oxidizing gas introduced into the same, and the heat produced by the oxidation process of the lead being used for melting a further charge of lead to be atomized. y

3. Apparatus for producing lead oxide comprising a rotary atomizing chamber, an oxidation chamber connected therewith and provided with means for comminuting the lead oxide falling down and settling at the bottom of said oxidation chamber, means for producing heating gases admitted into the atomizing chamber, a device for receiving a further charge of lead arranged within the oxidizing chamber and capable of being heated by the heat produced in the combustion of lead to lead oxide. f

PAUL KEMP.

EMANUEL FEUER. 

